Well cleaner

ABSTRACT

A device for cleaning and/or disinfecting commercial wells consisting of a tubular housing smaller in diameter than the well casing and which is lowered to a location below the liquid level in the well. A resonant diaphragm partition separates the housing into an upper closed chamber and a lower open chamber. Centrally mounted on the upper portion of the diaphragm is a rotational mass which revolves at constant speed and the mass-speed relationship develops sinusoidal vibrations in the low-sonic range and substantially vertical to its diaphragm mount location. The sinusoidal force excites the diaphragm into one of its modes of natural frequency in the form of bending wave motion in the diaphragm. The force, sinusoidal in nature, thus released also excites the housing of the upper and lower chambers and longitudinal bending waves are in turn continuously developed and transmitted through the material of the housing and in a direction through the lower open end portion of the cylindrical housing. The longitudinal bending wave vibrations in the material of the cylindrical housing in turn cause compressional acoustic waves to be transmitted through the surrounding water medium at speeds approximating 4,800 feet per second from both the inner and outer surfaces of the lower open end cylindrical shell, and from the outer surface of the upper closed cylindrical shell. The direction of the released compressional sound waves is perpendicular to surfaces of the cylindrical shell and the waves are multidirectional in nature.

[ Mar, M, 1972 Vernon 11). Beehler, Los Angeles, Calif. a part interest22 Filed: Sept. 4, 11970 21 Appl.No.: 69,8416

[72] Inventor:

[73] Assignee:

[ ABSTRACT A device for cleaning and/or disinfecting commercial wellsconsisting of a tubular housing smaller in diameter than the well casingand which is lowered to a location below the liquid level in the well. Aresonant diaphragm partition separatesthe housing into an upper closedchamber and a lower open chamber. Centrally mounted on the upper portionof the diaphragm is a rotational mass which revolves at constant speedand the mass-speed relationship develops sinusoidal vibrations in thelow-sonic range and substantially vertical to its diaphragm mountlocation. The sinusoidal force excites the diaphragm into one of itsmodes of natural frequency in the form of bending wave motion in thediaphragm. The force, sinusoidal in nature, thus released also excitesthe housing of the upper and lower chambers and longitudinal bendingwaves are in turn continuously developed and transmitted through thematerial of the housing and in a direction through the lower open endportion of the cylindrical housing. The 10ngitudinal bending wavevibrations in the material of the cylindrical housing in turn causecompressional acoustic waves to be transmitted through the surroundingwater medium at speeds approximating 4,800 feet per second from both theinner and outer surfaces of the lower open end cylindrical shell, andfrom the outer surface of the upper closed cylindrical shell. Thedirection of the released compressional sound waves is perpendicular tosurfaces of the cylindrical shell and the waves are multidirectional innature.

64 6 u, 12 Drawing Figures [51] lntJCfl .JEZ111td3/27 [58]PleldoiiSearch ..l66/177,3l1,249;175/56 [56] References Cited UNITEDSTATES PATENTS 2,816,612 12/1957 l-lutchison etal ..166/177 2,871,9432/1959 Bodine ...166/l77X 2,918,126 12/1959 Bodine ..166/249 3,101,4998/1963 Greenfield. 166/177X 3,194,326 7/1965 Bodine ..175/56 3,209,83410/1965 Essary 166/177 3,402,611 9/1968 Schwenzfeier. .....l75/56X3,527,300 9/1970 Phillips ..166/l77X Primary Examiner-David H. BrownAttorney-BeehlerdzArant if g. 7 7

E i m i i 1 l 1 I I l 1 1 s E l l 1 1 i 1 1 I 54 l i 1 1 52 PAIENTEDMAR14 I972 3, 648 769 SHEEI 3 OF 4 INVENTOR Haze/.0 I; Saws 5 2IQTTOENEVQS' WELL CLEANER It is well known to the state of the art thata structure can be so designed, with materials of known modulus,dimensions and configurations that have known .moments of inertia, andthat in combination with specific mass densities the structural naturalfrequency and modes can be predetermined and be resonant with anydiscreet frequency. In this instance the structure is designed to be atits maximum efficiency for its defined purpose in that it is resonantand its transmissibility and amplification of sonic energy generated inthe form of sound waves is at a maximum.

It is well known in the art that all liquids have resonant frequencybands. The subj ect structure is designed to be resonant with its inputfrequency and is at'its maximum efficiency in terms of output to input.The resulting transmissibility of sonic energy compressional sound wavesexcites, resonates and causes cavitation with the fluid in the wellsurrounding and adjacent the device.

The cleaning action of the sonic energy device is based to a majorextent on the phenomenon called cavitation. The implosion of minutecavities or bubbles which are produced by pressure differentials imposedwithin the solution at the inner well surface and areas of wellincrustation account for the cavitation. I

The cleaning and/or disinfecting capability of the device is furtherenhanced by means of release of acid chemicals, such as chlorine gas, tothe solution within the lower shell of the device. Such chemicals areforced by mechanical and cavitational energy through the holes in thelower shell to the pipe surface to be cleaned and are subjected tointense cavitational energy at the well surface and throughout theincrusted areas in the presence of well water to increase the rate ofcleaning or disinfecting, as the case may be. Acid chemicals or chlorinegas, when injected into the water area, cause a foaming solu tion andthe bubbles of the solution are caused to alternately expand and tocollapse and to leave a void or hole in the foam solution when subjectedto the action of the compressional sound waves. The foam solution rushesto fill the void or vacuum, creating tremendous transitory vacuums andalternative pressures. The alternate vacuum and pressure action of thesound waves constitute the major aspect of a properly designed andefficient sonic energy cleaning system.

Among the objects of the invention is to provide a new and improvedcleaner for wells which is very penetrating in its effect upon the wallsof the liner and casing, as well as in the adjacent formation, but whichis not drastic in its performance so that there is no prospect of damageto the liner or casing or the future ability of the well to produce.

Still another object of the invention is to provide a new and improvedwell cleaning apparatus which can be lowered easily and inexpensivelyinto a well needing cleaning and set in operation upon reaching theprecisely desired depth and which, moreover, can be shifted throughoutan appreciable vertical distance on those occasions where the producingstrata is many times thicker than the length of the apparatus so thatwith only a single drop of the apparatus into the well all portions ofthe liner needing cleaning can be cleaned before the apparatus isremoved.

Still another object of the invention is to provide a new and improvedwell cleaner operating on the vibration principle in which can beincorporated a chlorinating device or other type of liquid dispenserwhich can be operated simultaneously with the cleaning operation andwhich is caused to more effectively perform its work in the well byreason of the vibration energy present for the cleaning operation.

Still another object of the invention is to provide a new and improvedmethod for cleaning wells which makes use of vibration energy in the lowsonic range so that the vibration energy after being generated in theapparatus is caused to travel through the liquid in the well to thesurrounding liner and producing formation thereby making use ofvibration for cleaning and also treating in such fashion that there isno likelihood of damage resulting to the well.

With these and other objects in view, the invention consists in theconstruction, arrangement, and combination of the various parts of thedevice, whereby the objects contemplated are attained, as hereinafterset forth, pointed out in the appended claims and illustrated in theaccompanying drawings.

In the drawings:

FIG. 1 is a longitudinal sectional view of a typical well showing thewell cleaner lowered to a location below the top of the liquid levelnear the bottom of the well.

FIG. 2 is a longitudinal sectional view showing the interiorconstruction of the apparatus.

FIG. 3 is a longitudinal sectional view on the line 3-3 to FIG. 2.

FIG. 4 is a cross sectional view on the line 4-4 of FIG. 2.

FIG. 5 is a fragmentary longitudinal sectional view on the circular line5 of FIG. 3.

FIG. 6 is a fragmentary longitudinal sectional view on the line 6-6 ofFIG. 2.

FIG. 7 is a longitudinal sectional view of the housing for the cleaningapparatus in one mode of vibration.

FIG. 8 is a view similar to FIG. 7 wherein the apparatus is in anothermode of vibration.

FIG. 9 is a cross sectional view on the line 9-9 of FIG. 7.

FIG. 10 is a longitudinal sectional view of another form of the device.

FIG. 11 is a cross sectional view on the line llll-1ll of FIG. 10.

FIG. 12 is a cross-sectional view on the line 12- In an embodiment ofthe invention chosen for the purpose of illustration there is shown awell I'll, extending down from the earth surface 11, and provided with acasing 12, which extends to the producing strata where the casing isprovided with a perforated liner 13. Production fluid which may be wateror petroleum as the case may be flows through the perforated liner intothe bottom of the well where it stands as a reservoir of fluid 14. Ahousing 15, containing appropriate cleaning apparatus is suspendedin'well 10, by means of an electrical sup porting cable 16. The cable iswound on a power-driven reel 17 and paid out over pulleys 18, at the endof adjusting arm 19. Additional pulleys 20, forming part of well headassembly 21, anchored to the top of the casing 12, center the line inthe well as the housing 15, is moved up or down as the case may be.

The housing 15, in the embodiment shown is cylindrical and has adiameter substantially less than the inside diameter of the casing 12,so that the housing can pass freely down into the well until its workhas been performed and can then be withdrawn therefrom with sufficientease so that this can be accomplished even though the casing may not beperfectly straight as is frequently the case in actual practice. Rubberbuttons 22 are provided to serve as bumpers to make certain that thehousing clears the surface of the casing on all sides.

Within the housing 15 is a partition 25 the center portion of which is astiff, flexible diaphragm 26 which separates the interior of the housinginto an upper closed chamber 27 and a lower open chamber 28.

A bracket 30 is secured to a boss 31 which is located at the center ofthe diaphragm 26, and secured thereto by means of bolts 32. The bracketsupports a motor 33, at opposite ends 34 and 35. The mountings for themotor on the bracket at opposite ends differ materially although bothserve as a means for holding the motor in operating position.

At the end 34 a drive shaft 36 from the motor extends into a bushing 37,as shown in FIG. 6, wherein it is secured in place by means of a setscrew 38 on an axis 39 eccentric with respect to the axis 40 of a stubshaft 41 forming part of the bushing 37. A bearing ring 42 rotatablymounts the stub shaft 41 at one end $3 of the bracket 30. From theforegoing description it will be apparent that in the embodiment of theinvention illustrated in FIGS. 1, 2, and 3, that the left end of themotor 33 is eccentrically mounted and when the drive shaft 36 is rotatedby operation of the motor, the mass of the motor will rotate cyclicallyabout the axis 40 of the resilient bearing mount thereby developing andtransmitting a sinusoidal force motion to bracket 30 at its end 43through the stub shaft 41.

At the end 35 of the casing of the motor 33, namely the end opposite tothat just described, there is a motor flange 45 bolted to a motor frame46 of the motor 33 by means of bolts 47 as shown in FIG. 5. A stub shaft48 extending outwardly from the base 45 is received in a resilientbearing assembly indicated generally by the reference character 49. Thebearing assembly in turn is anchored to another end 50 of the bracket 30by means of screws 51.

In the embodiment shown in FIG. there is a bearing sleeve 52 forming ahearing within which the stub shaft 48 is anchored in a stationaryposition by means of a pressed fit. Around the bearing sleeve is anannular resilient and vibration absorbing pad 53 which is held inposition by a retaining sleeve. A sleeve bearing 56 is press fitted andanchored to retaining sleeve 54. Sleeve bearing 56 is housed in asliding fit to a bearing 58 which is anchored to the bracket end 50. Adisc plate 55 is provided to fasten the bearing assembly in position bymeans of screws 51 and 57.

What is important for the mounting of the end 35 of the motor is that asubstantial portion of the vibration which is set up in the motor massby eccentric mounting at the opposite end 34 is prohibited from passingfrom the motor to the end 50, thereby making it necessary thatessentially all of the vibration travel through only the other end 43 ofthe bracket and then to a single connection between the bracket 30 andthe diaphragm 26 at the location of the boss 31.

An electric cable 60 connected to the motor extends upwardly through afitting 6l threadedly mounted at the center of a closure 62 for theupper end of the closed chamber 27. Hand holds 63 and 64 may be providedon the closure to facilitate handling when the apparatus is not in acondition of operation in the well.

For ease in manufacture an upper section 65 of the housing, is madeseparate and adopted to threadedly engage the partition 25 at the lowerend. Similarly a lower section 66 of the housing is adapted tothreadedly engage the partition 25 and has its entire lower end open asindicated by the reference character 67 as shown in FIGS. 2, 7, and 8.

In the embodiment described the lower section 66 may be of relativelylighter gage than the upper section 65 so that it has greater freedom toflex.

In operation of the device constructed as described the housing I5 islowered into a well to a location within the reservoir 14 of productionfluid, preferably below its upper surface 68. Holes 69 extending throughthe lower section 66 and the open lower end 67 permit fluid to passfreely into the lower open chamber 28 to a location adjacent theunderside of the partition 25.

Inasmuch as the upper chamber 27 is a closed chamber no fluid ispermitted to enter it and the chamber serves to provide buoyancy for theapparatus when it is submerged in production fluid 14. This isparticularly helpful in deep wells where the weight of a long length ofline 16 adds appreciably to the weight of the apparatus in the wellwhich must be supported by the upper end of the line.

After the housing has been lowered to its location within the productionfluid, the lowering operation is halted and power turned on to set themotor 33 in operation. The rate of rotation of the drive shaft 36 issynchronous as provided in this case by an AC induction motor and goodoperating conditions are experienced by design when the drive shaftrotates at a frequency in the low sonic region. Amplitude of the forcemotion vibrations set up in the diaphragm 26, by the eccentric mountingdescribed in connection with FIG. 6 is controllable by the relationshipbetween the axis 39 of the drive shaft and the axis 40 of the stubshaft, this being the degree of eccentricity of the drive shaftmounting.

By reason of the motor mountings described the sinusoidal forceexcitation is concentrated at the center of the diaphragm 26. Vibratoryaction of the diaphragm 26 is passed from its perimeter to the housingthe junction of the perimeter of the diaphragm and the housing forming anode as diagrammed in FIGS. 7 and 8. when operation is in the firstmode, as illustrated in FIG. 7, the upper section 65 of the housing isflexed as indicated by the broken lines 70 and 71 inasmuch as oppositeends of the upper section are anchored, namely, respectively to thepartition 25 of the lower end and to the closure 62 at the upper end.The lower section 66, however, vibrates in a different pattern in thatonly the upper end of the lower section is anchored, namely, to thepartition 25 and lower end being unsupported. The lower section will,therefore, vibrate as indicated by the broken lines 72 and 73.

Vibrations generated as described take place and produce cavitation inthe production fluid 14. The movement of the upper and lower sections ofthe casing have been greatly exag gerated in FIGS. 7 and 8 for purposesof illustration. In actual practice the movement is relatively small butadequate for setting up a corresponding cavitation effect in theproduction fluid 14. In point of fact, the sizes and masses of thediaphragm and other portions of the housing including upper and lowersections as well as the closure 62 are calculated so that for a selectedembodiment of the apparatus when subjected to vibration at a frequencyand amplitude provided by the motor 33 vibrate in a conditionapproaching resonance, namely, at one or more of their naturalfrequencies. This makes possible a very economical source of power whileachieving substantially a maximum transfer of energy from the motorthrough the apparatus and the production fluid to the perforated liner13 which needs to be cleaned. The liner surface is excited as a resultof the vibratory energy being passed to it by the fluid and the linertogether with dirt and incrustation particles on it, and theperforations in it are similarly excited and progressively loosened sothat the material thereby dislodged falls free to the bottom of thewell; The vibratory and cavitation cleaning action may be continued aslong as necessary until the well has been cleaned. An appropriate closedcircuit television may be employed to inspect the operation so that whenthe well is finally cleaned it will be observable by the operator,whereupon the cleaning action can be suspended and the apparatuswithdrawn from the well.

To additionally facilitate the cleaning of the well, as well as makingcertain of the condition of the production fluid, a cleaning fluid maybe dispensed, vibrated and excited simultaneously by the apparatus. Sucha cleaning fluid may be either a chlorinating compound or otherappropriate cleaning fluid, depending on the type of well being cleaned,the character of the production fluid, and other characteristics whichmay be met in any particular installation.

When cleaning fluid is to be dispensed, there is provided a capsule 75which is mounted in the lower open chamber 28 as shown in FIGS. 2 'and3. An effective mounting is one making use of a spider 76 having legs77, 78, and 79 the outer ends of which are fastened to plates 80 weldedor otherwise secured to the inside surface of the lower section 66. Atop plate 81 of the capsule 75 is anchored to the spider 76 by means ofa bolt 82, which extends upwardly through the capsule from a bottomplate 83 through a sleeve 84. Resilient shear mount bearings 74 areconnected between legs 77, 78, 79 and plates 80 to prevent vibrationfrom being transmitted to the capsule 75 and also to prevent restrictionof movement to the lower housing 66.

In the event that the capsule is to contain a dry treating material 85 awall 86 of the capsule may bemade of screen material so that as the drymaterial slowly dissolves, partly by reason of its nature and partly byreason of the fact that it is being cavitated, the cleaning materialwill pass progressively outwardly from the capsule into the productionfluid of the well where it will be thoroughly mixed as a result of thecavitation action as the cleaning operation progresses. A cover 87closes a feed port 88 by means of which'the material 85 may be fed intothe capsule prior to the beginning of the operation. Moreover, with acapsule constructed as shown, extra capsules may be kept in readinessand used as replacements for a spent capsule merely by unscrewing a nut89 at the lower end of the bolt $2 whereupon one capsule may be removedand another one applied.

In the second embodiment of the invention illustrated particularly inFIGS. MI, ill, and I2 a power source 90 for sinusoidal vibration energyis mounted upon a base 91 and the base in turn fastened to a boss 92forming part of the diaphragm 2a of the partition 25. Certain commercialindustrial vibrators are available of such character that, when inoperation, they are capable of vibrating sinusoidally any piece ofapparatus to which they may be attached by means of the base 9B.

In the embodiment of FIGS. 10 and Ill such a power source is oneelectrically operated and supplied by an electric cable Q3.

A second type of capsule 95 is shown in the apparatus of FIGS. 10 and I2and is of a character such that it can be substituted for the capsule 75previously described.

The capsule 95 is adapted to provide a reservoir 96 for pressurizedliquid acid material, the capsule having closed top and bottom plates 97and 93 respectively, and a cylindrical imperforate side wall 99. Fordispensing liquid from the capsule there is provided a dispensing ringMM) having small perforations lllll extending around the perimeter thering being fed through a supply pipe 102 connected to an outlet port 103in the bottom plate 9%. Appropriate valves MM and W5 are shown forregulating the flow A fill port I06 is shown provided with a shut-offvalve I07.

In this embodiment of the invention the housing is set in vibration inthe same manner as previously described by ac tion of the power sourcepassing to the diaphragm 26 and ultimately to the housing. Pressurizedliquid acid material, for example, released by the ring 100 is driven tothe well casing through holes 69 and cavitated at the well linersurface.

Having described the invention, what is claimed as new in support ofLetters Patent is:

ll. A well cleaner for wells having a casing extending into the earthfor collection of fluid prior to withdrawal, said cleaner comprising:

a housing,

a transverse partition dividing said housing into an upper chamber andthe lower chamber, a mass in said upper chamber cyclically rotating on asubstantially transverse axis, said mass when in a condition of rotationbeing a source of sinusoidal wave energy, and a source of power for saidcyclically rotating mass, a bracket located substantially centrally onsaid partition and connected to said source of sinusoidal wave energy,said partition being of relatively stiff resilient material anchored atits perimeter to said housing whereby sinusoidal motion conveyed to thepartition by said bracket is passed to the housing and vibration is setup thereby in said housing when at a location within said fluid wherebythe fluid passes said vibration to the wall of said casing to loosenmaterial lodged thereon.

2. A well cleaner as in claim ll, wherein there is a flexible power lineextending from ground surface into the well to said well cleaner, saidpower line being adjustable up and down to raise and lower the positionof said housing in the well.

'3. A well cleaner as in claim 1, wherein a motor having a body rotatingabout a substantially transverse axis provides said mass, an end of saidbody in alignment with said axis having a vibration isolating mountingon said housing, a rotating shaft for said motor having an end oppositesaid one end of the body having an eccentric mounting on :said bracket.

41. A well cleaner as in claim ll, wherein there is a tank for welltreating material mounted in said lower chamber at a location clear ofsaid housing, and material distributing means connected to said tankreceptive of quantities of said material, and outlet means included insaid material distributing means whereby said material is dispensed intothe fluid in the well in response to action by said source of sinusoidalwave energy.

5. A well cleaner as in claim I, wherein said upper chamber is air tightto rovide buoyancy for said cleaner in the fluid.

46. A well c eaner as in claim 5, wherein the housing around said lowerchamber is perforated to provide passage through said housing for saidfluid.

=l= l 1F k

1. A well cleaner for wells having a casing extending into the earth forcollection of fluid prior to withdrawal, said cleaner comprising: ahousing, a transverse partition dividing said housing into an upperchamber and the lower chamber, a mass in said upper chamber cyclicallyrotating on a substantially transverse axis, said mass when in acondition of rotation being a source of sinusoidal wave energy, and asource of power for said cyclically rotating mass, a bracket locatedsubstantially centrally on said partition and connected to said sourceof sinusoidal wave energy, said partition being of relatively stiffresilient material anchored at its perimeter to said housing wherebysinusoidal motion conveyed to the partition by said bracket is passed tothe housing and vibration is set up thereby in said housing when at alocation within said fluid whereby the fluid passes said vibration tothe wall of said casing to loosen material lodged thereon.
 2. A wellcleaner as in claim 1, wherein there is a flexible power line extendingfrom ground surface into the well to said well cleaner, said power linebeing adjustable up and down to raise and lower the position of saidhousing in the well.
 3. A well cleaner as in claim 1, wherein a motorhaving a body rotating about a substantially transverse axis providessaid mass, an end of said body in alignment with said axis having avibration isolating mounting on said housing, a rotating shaft for saidmotor having an end opposite said one end of the body having aneccentric mounting on said bracket.
 4. A well cleaner as in claim 1,wherein there is a tank for well treating material mounted in said lowerchamber at a location clear of said housing, and material distributingmeans connected to said tank receptive of quantities of said material,and outlet means included in said material distributing means wherebysaid material is dispensed into the fluid in the well in response toaction by said source of sinusoidal wave energy.
 5. A well cleaner as inclaim 1, wherein said upper chamber is air tight to provide buoyancy forsaid cleaner in the fluid.
 6. A well cleaner as in claim 5, wherein thehousing around said lower chamber is perforated to provide passagethrough said housing for said fluid.